strings.md

Strings

What is a String in Ruby?

String is a text with single-quote(' ') or double-quote(" ") .

Examples:

'This is a string in single quote'
"This is a string in double quote"

Interpolation

Interpolation allows a string includes Ruby expression

Using:

"#{expression}"

Examples:

ruby = "Ruby Programming"
"Welcome to #{ruby}" #=> "Welcome to Ruby Programming"
"1 + 2 = {1 + 2}"    #=> "1 + 2 = 3"

Indexing

string_ruby = "Welcome to String in Ruby"

• Get first character in string_ruby:

  irb:001> string_ruby[0]
  => "W"

• Get last character in string_ruby:

  irb:001> string_ruby[-1]
  => "y"

• Get second last character:

  irb:001> string_ruby[-2]
  => "b"

• Get first 7 characters:

  irb:001> string_ruby[0..6]
  => "Welcome"

• Get last 4 characters:

  irb:001> string_ruby[-4..-1]
  => "Ruby"

Common Methods in String

• Upcase a string

  irb:001> "hello world".upcase     
  => "HELLO WORLD"

• Downcase a string

  irb:001> "HELLO WORLD".downcase   
  => "hello world"

• Reverse characters in a string

  irb:001> "hello world".reverse    
  => "dlrow olleh"

• Capitalize first character in a string

  irb:001> "hello world".capitalize 
  => "Hello world"

• Get length of a string

  irb:001> "hello world".length     
  => 11

• Replace a character in string by a new character

  irb:001> "hello world".gsub("l", "L") 
  => "heLLo worLd"